多巴胺在聚甘氨酸化学修饰电极上的催化氧化及其痕量测定  

Catalytic Oxidation of Dopamine at Polyglycine Chemically Modified Electrode and its Trace Determination

作　　者：王艳玲[1] 刘海燕[1] 张国荣[1] 

机构地区：[1]山东师范大学化学系,济南,250014

出　　处：《化学传感器》2002年第1期44-51,共8页Chemical Sensors

摘　　要：用方波伏安法研究了多巴胺在电聚合甘氨酸膜修饰电极上的电化学行为,该修饰电极对多巴胺的氧化具有明显的催化作用,氧化峰电位负移,氧化电流明显增大,使得测定灵敏度显著提高。本文通过实验选择了最佳聚合时间,最佳pH条件,讨论了温度的影响以及反应机理。该电极有较宽的线性范围:2.5×10^(-7)～1.2×10^(-4)mol/L,检出限(信噪比=3)为8.0×10^(-9)mol/L。对5×10^(-5)mol/L多巴胺平行测定8次相对标准偏差为1.4％,该电极有效地排除了抗坏血酸的干扰,具有良好的稳定性和重现性,被用于样品中多巴胺的测定。Square wave voltammetry has been used to research the electrochemical behaviour of dopamine on the glycine modified electrode fabricated by electropolymerizing procedure. The modified electrode has obvious catalytic action for oxidation of dopamine, reducing the overpo-tentials by about 300mV, increasing greatly the anoic peak current and improving significantly the sensitivity of the measurements. In our experiment, the optimum condition including the pH of buffer solution, time of electropolymerization and the influnce of temprature was explored. The mechanism of electrode reaction was given. The electrode have a wide linear range of 2. 5×10-7 - 1. 2×10-4mol/L. The detection limit is 8. 0×10-9mol/L(S/N = 3). The relative standard deviation for eight determinations of 5×10-5mol/L dopamine was 1.4%. The modified electrode, which eliminatde effiently the interference from ascorbic acid(AA), showed excellent stability and reproducibility. The modified electrode has been used to measure dopamine in real samples.

关 键 词：电催化氧化 多巴胺 聚甘氨酸 化学修饰电极 安培测定 痕量测定 

分 类 号：O657.1[理学—分析化学]